swagelok.com
Thread and
End Connection
Identification Guide
Table of Contents
Introduction
Thread and End Connection Terminology . . . . . . . . . . . 5
General Terminology . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
Step-by-Step Identification
Procedure for Threads and
End Connections . . . . . . . . . . . . . . . . . . . . . . . . 7
Thread Identification
Reference Tables. . . . . . . . . . . . . . . . . . . . . . . 13
Tapered Threads. . . . . . . . . . . . . . . . . . . . . . . .21
End Connections That Use:
Tapered Threads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Straight Threads. . . . . . . . . . . . . . . . . . . . . . . . 27
End Connections That Use:
Unified Screw Threads . . . . . . . . . . . . . . . . . . . . . . . . . 29
ISO 228/1 Threads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 36
Metric (ISO 261) Threads. . . . . . . . . . . . . . . . . . . . . . . . 43
NPSM Threads. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 50
Appendix
End Connection to Thread Matrix. . . . . . . . . . . . . . . . . 51
Thread to End Connection Matrix. . . . . . . . . . . . . . . . . 52
Thread Identification Tools . . . . . . . . . . . . . . . . . . . . . . 53
Glossary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 54
About Swagelok Company
Identification
Introduction
Swagelok Company is an approximately $2 billion
privately held developer of fluid system products,
assemblies, and services for the oil and gas,
chemical and petrochemical, semiconductor, and
transportation industries. Headquartered in Solon,
Ohio, U.S.A., Swagelok serves customers through
200 sales and service centers in 70 countries,
supported by the expertise of 5,500 corporate
associates at 20 manufacturing facilities and five
global technology centers.
Appendix
Straight
Tapered
Tables
For more information or assistance please contact
your authorized Swagelok sales and service center
or visit our website at www.swagelok.com.
4
Introduction
Introduction
Thread and End Connection
Terminology
Standards are used to help identify threads
and end connections. We will use the following
definitions in this manual:
Identification
Thread Standard
A specific reference to a formal standard (for
example, ASME B1.1, EN 10226-1, or ISO 261) that
describes thread form, including a thread’s angle,
pitch, and diameter.
End Connection Standard
Tables
A specific reference to a national standard (such
as DIN 3852 or JIS R and JIS Rc) or industry group
standard (such as SAE J512) that describes an end
connection’s components, seal area, geometry,
and nominal sizes. Thread standards are usually
referenced in the end connection standard.
Thread Standards and End Connection
Standards
Tapered
Many mechanical end connections have threads.
Therefore, thread standards can be used to help
define end connection standards.
Pitch
Straight
For the purposes of this guide, pitch refers to
threads per inch, instead of the distance between
the threads, for fractional screw threads and pipe
threads. For all metric screw threads, pitch refers to
the distance between adjacent threads.
Appendix
5
General Terminology
Introduction
General terms and characteristics, which apply to all
end connection threads, are shown below for both
male and female threads.
Threads
Identification
1. Crest
2. Root
3. Flank
4. Pitch (metric)
4
6
Tables
7
1 23
5. Thread flank angle
6. Taper angle
7. Male thread OD
8. Female thread ID
8
5
Tapered
Male
End Connections
1. Body size
2. Shoulder
3. Face
Female
1
2
Straight
3
Appendix
End Connection
6
Introduction
Step-by-Step Identification
Procedure for Threads
and End Connections
Step 1:Determine if the thread is tapered or
straight (parallel).
Measure the thread diameter.
Step 3:
Determine the thread pitch.
Step 4:
Determine the thread standard.
Step 5:
Identify the end connection.
Identification
Step 2:
Note:Even experienced workers
sometimes have difficulty identifying
threads, regardless of their thread
identification procedure and the quality
of their gauges.
Tables
Details
Step 1:Determine if the thread is
T tapered or S straight (parallel).
T
If the diameters increase for a male end or
decrease for a female end, the thread is
tapered.
S
If all the diameters are the same, the thread is
straight (parallel).
Tapered
Use a caliper to measure the nominal male or
female thread crest-to-crest diameter on the first,
fourth, and last full threads (Fig. 1).
Straight
Appendix
Last
4th
1st
Fig. 1
Measuring Crest-to-Crest Thread Diameters
7
Introduction
Last
4th
1st
4th
1st
T
Last
Identification
S
Fig. 2
Measuring the Thread Diameters
Step 2: Measure the thread diameter.
Tables
Use a caliper to measure the nominal male or
female thread diameter from crest-to-crest (Fig. 2).
T
Measure the fourth or fifth full thread.
S
Measure any full thread.
Tapered
The diameter measurement obtained in this step
may not be exactly the same as the listed nominal
size for the given thread. The main reason for this
variation is industry or manufacturing tolerances.
Step 3: Determine the thread pitch.
Appendix
Straight
To determine the thread pitch, use the Swagelok®
pitch gauges and check the thread against each
form until you find a match. If you prefer to narrow
down the choices, use the following procedure:
8
a.
On the appropriate thread identification
reference table, locate the nominal thread
diameter. Note that it is common to have the
thread diameter for different threads listed
multiple times.
T
Turn to the Tapered Thread Identification
Reference Tables beginning on page 13.
S
Turn to the Straight Thread Identification
Reference Tables beginning on page 15.
For each case, read across the table to the
pitch column to determine the possible thread
pitches for your thread.
c.
Try the appropriate pitch gauge form for the
threads identified in Step b. above until you
find a match (Fig. 3).
18 threads
per inch
No Match
Match
Identification
1.5 mm per
thread
Introduction
b.
Fig. 3.
Determining the Thread Pitch
Tables
Step 4: Determine the thread standard.
Tapered
Once you have determined the following about
a thread, you have all the information required to
identify it:
■ Male or female
■ Straight or tapered
■ Nominal male or female diameter
■ Pitch
Now, turn to the appropriate thread identification
reference table and identify the thread.
Step 5: Identify the end connection.
a.
Locate the end connections that have the
tapered thread you identified. (See pages
21 through 26.
b.
Study the cross-section drawings for these
end connections and determine which one
matches your end connection.
Appendix
If the thread is tapered:
Straight
T
9
Introduction
S
If the thread is straight:
a.
Locate the end connections that use the
straight thread you identified. (See pages 27
through 50.
b.
Study the cross-section drawings for these end
connections and determine which one matches
your end connection.
Tables
Identification
Note:The Swagelok combination seat and
pitch gauge set includes 45°, 37°, and
30° seat angle gauges to assist with end
connection identification. (See page 53.)
c.
Select one of the gauges and place its angle
against the seat angle of the end connection.
d.
If the center line of the fitting and the longitudinal
axis of the gauge are parallel, the seat angle and
the gauge angle are the same. If not, try another
gauge.
Tapered
Longitudinal axis
Center line
No Match
Seat angle
Straight
Seat gauge angle
Match
Appendix
Fig. 4
Determining Seat Angle
Note:Fittings have seat angles other than 45°,
37°, and 30°. Contact your authorized
Swagelok sales and service center for
additional information.
10
Introduction
EXAMPLE:
Thread and End Connection
Identification (Steps 1 to 5)
You have a male fitting and you need to identify
its thread.
Step 1:
Determine if the thread is tapered
or straight (parallel).
Identification
You find that the thread is straight.
Step 2:
Measure the thread diameter.
You find the thread diameter to be 0.430 in.
Step 3:
a.
Determine the thread pitch.
Nominal
Thread
Size
Designation
3/8
1/2
Nominal Male
Thread Diameter
in.
mm
Pitch➀
Page
UNF
0.375 to 0.363
9.53 to 9.22
24U
30 to 35
NPSM
0.658
16.71
18U
51
ISO 228/1
0.656
16.66
19W
36 to 43
UNS
0.436 to 0.429 11.07 to 10.90
24U
30 to 35
UNF
0.436 to 0.424 11.07 to 10.77
20U
30 to 35
UNF
0.500 to 0.487 12.70 to 12.36
20U
30 to 35
NPSM
0.818
20.78
14U
51
ISO 228/1
0.825
20.96
14W
36 to 43
Tapered
7/16
Tables
Because the thread is straight, turn to the
Straight Thread Identification Reference
Table, page 15, and locate the thread
diameter. See section of table below.
Straight
➀U = Unified W = Whitworth M = Metric
Labeling on each Swagelok pitch gauge form
Look across the table to find the
corresponding pitches. In this case, they
are 20 and 24.
c.
Therefore, to determine the pitch of the thread
you would use your 20 and 24 pitch gauges.
Appendix
b.
For the purposes of this example, assume that
the pitch is 24.
11
Introduction
Step 4: Determine the thread standard.
At this point you know that the thread has the
following characteristics:
a.Male
Identification
b.Straight
c.
Nominal thread diameter of 0.430 in.
d.
Pitch equals 24
Looking at the cut-out portion of the straight
thread identification reference table, you see that
the only thread with all of these characteristics is
a 7/16 in. UNS thread.
Step 5: Identify the end connection.
Appendix
Straight
Tapered
Tables
So far you know that you have a 7/16 in. UNS
thread. To identify the end connection, you:
12
a.
Identify the type of seal.
b.
Turn to the End Connections That Use
Unified Screw Threads section in this
manual (pages 29 through 35, and
find the configuration that matches your
end connection.
Introduction
Thread Identification
Reference Tables
Tapered—Male
T
Note:Measured thread diameters may not match table
measurements exactly. All threads have tolerances
regarding many parts of the threads. The information in
this table is not intended to be used as inspection criteria
for threaded fittings. It is intended to be used as a guide to
help identify various threads.
1/16
1/8
3/8
1/2
3/4
1 1/4
1 1/2
mm
Pitch➀
0.304
7.72
28W
26
NPT
0.308
7.84
27U
24 to 25
ISO 7/1
0.383
9.73
28W
26
NPT
0.401
10.18
27U
24 to 25
ISO 7/1
0.518
13.16
19W
26
NPT
0.533
13.54
18U
24 to 25
ISO 7/1
0.656
16.86
19W
26
NPT
0.668
16.98
18U
24 to 25
ISO 7/1
0.825
20.96
14W
26
NPT
0.832
21.14
14U
24 to 25
ISO 7/1
1.041
26.44
14W
26
NPT
1.043
26.49
14U
24 to 25
24 to 25
Page
NPT
1.305
33.14
11.5U
ISO 7/1
1.309
33.25
11W
26
NPT
1.649
41.90
11.5U
24 to 25
ISO 7/1
1.650
41.91
11W
26
ISO 7/1
1.882
47.80
11W
26
NPT
1.888
47.97
11.5U
24 to 25
ISO 7/1
2.347
59.61
11W
26
NPT
2.362
60.00
11.5U
24 to 25
➀U = Unified
W = Whitworth
Labeling on each Swagelok pitch gauge form
Straight
2
in.
ISO 7/1
Tapered
1
Nominal Male
Thread Diameter
Tables
1/4
Identification
Nominal
Thread
Size, in. Designation
M = Metric
Note:1/2 and 3/4 in. ISO 7/1 and NPT threads can be difficult
to identify because they are very close in design. Positive
identification may not be possible without the use of an
optical comparator. Contact your authorized Swagelok sales
and service center for additional information.
Appendix
13
Tapered—Female
T
Introduction
Note:Measured thread diameters may not match table
measurements exactly. All threads have tolerances
regarding many parts of the threads. The information in
this table is not intended to be used as inspection criteria
for threaded fittings. It is intended to be used as a guide to
help identify various threads.
Identification
Nominal
Thread
Size, in. Designation
1/16
1/8
1/4
Tables
3/8
1/2
3/4
Tapered
1
1 1/4
1 1/2
2 1/4
Nominal Female
Thread Diameter
in.
mm
Pitch➀
Page
NPT
0.244
6.22
27U
24 to 25
ISO 7/1
0.258
6.56
28W
26
NPT
0.336
8.54
27U
24 to 25
ISO 7/1
0.337
8.57
28W
26
NPT
0.436
11.07
18U
24 to 25
ISO 7/1
0.451
11.45
19W
26
NPT
0.571
14.49
18U
24 to 25
ISO 7/1
0.589
14.95
19W
26
NPT
0.705
17.90
14U
24 to 25
ISO 7/1
0.734
18.63
14W
26
NPT
0.914
23.21
14U
24 to 25
ISO 7/1
0.949
24.12
14W
26
NPT
1.148
29.15
11.5U
26
ISO 7/1
1.193
30.29
11W
24 to 25
24 to 25
NPT
1.491
37.87
11.5U
ISO 7/1
1.534
38.95
11W
26
NPT
1.730
43.49
11.5U
24 to 25
ISO 7/1
1.766
44.85
11W
26
NPT
2.203
55.95
11.5U
24 to 25
ISO 7/1
2.231
56.66
11W
26
➀U = Unified
Straight
W = Whitworth
Labeling on each Swagelok pitch gauge form
M = Metric
Appendix
Note:1/2 and 3/4 in. ISO 7/1 and NPT threads can be difficult
to identify because they are very close in design. Positive
identification may not be possible without the use of an
optical comparator. Contact your authorized Swagelok
sales and service center for additional information.
14
Straight—Male
S
Nominal
Thread
Size
Designation
Introduction
Note:Measured thread diameters may not match table
measurements exactly. All threads have tolerances
regarding many parts of the threads. The information in
this table is not intended to be used as inspection criteria
for threaded fittings. It is intended to be used as a guide to
help identify various threads.
Nominal Male
Thread Diameter
in.
mm
Pitch➀
Page
Identification
Fractional, in.
1/16
1/8
1/4
5/16
7/16
9/16
5/8
11/16
13/16
7/8
28W
36 to 42
9.73
28W
36 to 42
NPSM
0.394
10.01
27U
50
ISO 228/1
0.518
13.16
19W
36 to 42
0.522
13.26
NPSM
18U
50
UNF
0.313 to 0.301 7.95 to 7.77
24U
30 to 35
UN
0.313 to 0.305 7.95 to 7.75
28U
30 to 35
UNF
0.375 to 0.363 9.53 to 9.22
24U
30 to 35
NPSM
0.658
16.71
18U
50
ISO 228/1
0.656
16.66
19W
36 to 42
UNS
0.436 to 0.429 11.07 to 10.90
24U
30 to 35
UNF
0.436 to 0.424 11.07 to 10.77
20U
30 to 35
UNF
0.500 to 0.487 12.70 to 12.36
20U
30 to 35
NPSM
0.818
20.78
14U
50
ISO 228/1
0.825
20.96
14W
36 to 42
UNF
0.563 to 0.548 14.29 to 13.92
18U
30 to 35
UNF
0.625 to 0.611 15.88 to 15.52
18U
30 to 35
14W
36 to 42
ISO 228/1
0.902
22.91
UN
0.688 to 0.677 17.46 to 17.19
16U
30 to 35
UNS
0.749 to 0.740 19.02 to 18.80
18U
30 to 35
UNF
0.750 to 0.734 19.05 to 18.65
16U
30 to 35
NPSM
1.029
26.14
14U
50
ISO 228/1
1.041
26.44
14W
36 to 42
UN
0.813 to 0.802 20.64 to 20.36
16U
30 to 35
UNF
0.875 to 0.858 22.23 to 21.79
14U
30 to 35
UNS
0.874 to 0.865 22.20 to 21.97
18U
30 to 35
14W
36 to 42
ISO 228/1
1.189
30.20
Straight
3/4
7.72
0.383
Tapered
1/2
0.304
ISO 228/1
Tables
3/8
ISO 228/1
W = Whitworth
M = Metric
Labeling on each Swagelok pitch gauge form
(continued on next page)
15
Appendix
➀U = Unified
Straight—Male
Introduction
S
Nominal
Thread
Size
Designation
Nominal Male
Thread Diameter
in.
mm
Pitch➀
Page
14U
30 to 35
Fractional, in.
UNS
Identification
1
1.287
32.69
11.5U
50
ISO 228/1
1.309
33.25
11W
36 to 42
1 1/16
Tables
1.063 to 1.049 27.00 to 26.64 12, 14U 30 to 35
UN
1.063 to 1.051 27.00 to 26.70
ISO 228/1
1 3/16
UN
UNF
16U
30 to 35
11W
36 to 42
1.188 to 1.174 30.16 to 29.83
12U
30 to 35
1.250 to 1.231 31.75 to 31.57
12U
30 to 35
1.492
37.90
NPSM
1.632
41.45
11.5U
50
ISO 228/1
1.650
41.91
11W
36 to 42
1 5/16
UN
1.313 to 1.299 33.34 to 33.00
12U
30 to 35
1 3/8
UNF
1.375 to 1.356 34.93 to 34.44
12U
30 to 35
1 7/16
UN
1.438 to 1.424 36.51 to 36.18
12U
30 to 35
1 1/2
Tapered
UN
1 1/8
1 1/4
1.000 to 0.983 25.40 to 24.97
NPSM
NPSM
1.871
47.52
11.5U
50
ISO 228/1
1.882
47.80
11W
36 to 42
1 5/8
UN
1.625 to 1.612 41.28 to 40.94 12, 20U 30 to 35
1 11/16
UN
1.688 to 1.674 42.86 to 42.53
1 3/4
ISO 228/1
1 7/8
UN
UN
2
ISO 228/1
NPSM
2 1/2
UN
12U
30 to 35
11W
36 to 42
1.875 to 1.862 47.63 to 47.29
12U
30 to 35
2.000 to 1.987 50.80 to 50.46
12U
30 to 35
36 to 42
2.116
53.75
2.347
59.61
11W
2.345
59.56
11.5U
50
12U
30 to 35
2.500 to 2.487 63.50 to 63.16
Straight
Metric, mm
8
0.310
7.88
1.0M
43 to 49
10
0.389
9.88
1.0M
43 to 49
0.467
11.85
1.5M
43 to 49
0.468
11.88
1.0M
43 to 49
14
0.545
13.85
1.5M
43 to 49
16
0.624
15.85
1.5M
43 to 49
18
0.703
17.85
1.5M
43 to 49
Appendix
12
Metric
➀U = Unified
W = Whitworth
M = Metric
Labeling on each Swagelok pitch gauge form
(continued on next page)
16
Straight—Male
S
Introduction
Nominal
Thread
Size
Designation
Nominal Male
Thread Diameter
in.
mm
Pitch➀
Page
Metric, mm
1.5M
24
0.939
23.85
1.5M
26
1.018
25.85
1.5M
1.056
26.82
2.0M
1.057
26.85
1.5M
1.174
29.82
2.0M
1.175
29.85
1.5M
1.292
32.82
2.0M
1.293
32.85
1.5M
1.410
35.82
2.0M
1.411
35.85
1.5M
1.490
37.85
1.5M
1.528
38.82
2.0M
1.530
38.85
1.5M
1.647
41.82
2.0M
1.648
41.85
1.5M
1.765
44.82
2.0M
1.766
44.85
1.5M
1.883
47.82
2.0M
1.884
47.85
1.5M
1.961
49.82
2.0M
2.040
51.82
2.0M
2.041
51.85
1.5M
56
2.198
55.82
2.0M
60
2.355
59.82
27
30
33
36
38
Metric
39
42
45
48
50
52
➀U = Unified
W = Whitworth
Labeling on each Swagelok pitch gauge form
43 to 49
Straight
1.5M
21.85
Tapered
19.85
0.860
Tables
0.781
22
Identification
20
2.0M
M = Metric
Appendix
Note:1/2 and 3/4 in. ISO 7/1 and NPT threads can be difficult
to identify because they are very close in design. Positive
identification may not be possible without the use of an
optical comparator. Contact your authorized Swagelok
sales and service center for additional information.
17
Straight—Female
S
Introduction
Note:Measured thread diameters may not match table
measurements exactly. All threads have tolerances
regarding many parts of the threads. The information in this
table is not intended to be used as inspection criteria for
threaded fittings. It is intended to be used as a guide to help
identify various threads.
Identification
Nominal
Thread
Size
Designation
Nominal Female
Thread Diameter
in.
mm
Pitch➀
Page
Fractional, in.
1/16
1/8
1/4
Tables
5/16
3/8
7/16
Tapered
1/2
9/16
5/8
ISO 228/1
0.259
6.56
28W
36 to 42
ISO 228/1
0.337
8.57
28W
36 to 42
NPSM
0.361
9.17
27U
50
ISO 228/1
0.451
11.45
19W
36 to 42
NPSM
0.474
12.04
18U
50
UNF
0.277 to 0.267
7.04 to 6.78
24U
30 to 35
UN
0.281 to 0.274
7.14 to 6.96
28U
30 to 35
UNF
0.340 to 0.330
8.64 to 8.38
24U
30 to 35
ISO 228/1
0.589
14.95
19W
36 to 42
NPSM
0.608
15.44
18U
50
UNF
0.395 to 0.383 10.03 to 9.73
20U
30 to 35
UNS
0.402 to 0.392 10.21 to 9.96
24U
30 to 35
UNF
0.457 to 0.446 11.61 to 11.33
20U
30 to 35
36 to 42
ISO 228/1
0.734
18.63
14W
NPSM
0.753
19.13
14U
50
18U
30 to 35
UNF
0.515 to 0.502 13.08 to 12.75
UNF
0.578 to 0.565 14.68 to 14.35
ISO 228/1
Straight
11/16
3/4
0.811
20.59
18U
30 to 35
14W
36 to 42
UN
0.634 to 0.620 16.10 to 15.75
16U
30 to 35
UNS
0.703 to 0.690 17.86 to 17.53
18U
30 to 35
UNF
0.707 to 0.682 17.96 to 17.32
16U
30 to 35
36 to 42
ISO 228/1
0.949
24.12
14W
NPSM
0.964
24.49
14U
50
13/16
UN
0.759 to 0.745 19.28 to 18.92
16U
30 to 35
UNF
0.814 to 0.798 20.68 to 20.27
14U
30 to 35
7/8
UNS
0.828 to 0.815 21.03 to 20.70
18U
30 to 35
14W
36 to 42
ISO 228/1
27.88
W = Whitworth
M = Metric
Labeling on each Swagelok pitch gauge form
(continued on next page)
Appendix
➀U = Unified
1.098
18
Straight—Female
S
Introduction
Nominal
Thread
Size
Designation
Nominal Female
Thread Diameter
in.
mm
Pitch➀
Page
Fractional, in.
15/16
1
UN
0.847 to 0.865 21.51 to 21.97
12U
30 to 35
UNS
0.938 to 0.923 23.83 to 23.44
14U
30 to 35
1.193
30.29
11W
36 to 42
NPSM
1.206
30.63
11.5U
50
1 1/16
UN
1 1/8
ISO 228/1
11W
36 to 42
1 3/16
UN
1.115 to 1.097 28.32 to 27.86
12U
30 to 35
UNF
1.178 to 1.160 29.92 to 29.45
12U
30 to 35
36 to 42
1 1/4
1.376
34.94
ISO 228/1
1.534
38.95
11W
NPSM
1.550
39.37
11.5U
50
12U
30 to 35
12U
30 to 35
UNF
1.303 to 1.285 33.10 to 32.64
UN
1.365 to 1.347 34.67 to 34.21
1 7/16
1 1/2
0.990 to 0.972 25.15 to 24.69 12, 14U 30 to 35
NPSM
1.780
45.47
11.5U
50
ISO 228/1
1.766
44.85
11W
36 to 42
UN
1.582 to 1.535 40.18 to 38.99 12, 20U 30 to 35
UN
1.615 to 1.59 41.02 to 40.56
1 3/4
ISO 228/1
1 7/8
UN
UN
2
12U
30 to 35
11W
36 to 42
1.803 to 1.785 45.80 to 45.35
12U
30 to 35
1.928 to 1.910 48.97 to 48.51
12U
30 to 35
36 to 42
2.000
50.79
ISO 228/1
2.231
56.66
11W
NPSM
2.264
57.51
11.5U
50
12U
30 to 35
2 1/2
UN
2.428 to 2.410 61.67 to 61.21
Tapered
1 5/8
1 11/16
Tables
1 3/8
Identification
ISO 228/1
Metric, mm
0.286
7.98
1.0M
10
0.356
9.04
1.0M
0.430
10.92
1.5M
0.444
11.27
1.0M
0.509
12.92
1.5M
12
Metric
14
Straight
8
43 to 49
➀U = Unified
W = Whitworth
M = Metric
Labeling on each Swagelok pitch gauge form
(continued on next page)
Appendix
19
Straight—Female
Introduction
S
Nominal
Thread
Size
Designation
Nominal Female
Thread Diameter
in.
mm
Pitch➀
Page
Identification
Metric, mm
16
0.587
14.92
1.5M
18
0.666
16.92
1.5M
20
0.745
18.92
1.5M
22
0.824
20.92
1.5M
24
0.887
22.53
1.5M
26
0.966
24.53
1.5M
1.005
25.53
1.5M
1.007
25.58
2.0M
1.125
28.58
2.0M
1.139
28.92
1.5M
1.241
31.53
1.5M
1.243
31.58
2.0M
1.359
34.53
1.5M
1.361
34.58
2.0M
1.438
36.53
1.5M
1.477
37.53
1.5M
1.479
37.58
2.0M
1.596
40.53
1.5M
1.598
40.58
2.0M
1.694
43.02
2.0M
1.729
43.92
1.5M
1.832
46.53
1.5M
1.834
46.57
2.0M
1.891
48.02
2.0M
1.969
50.02
2.0M
1.989
50.23
1.5M
56
2.149
54.57
2.0M
60
2.284
58.02
27
Tables
30
33
36
38
Metric
Tapered
39
42
45
48
Straight
50
52
W = Whitworth
Labeling on each Swagelok pitch gauge form
Appendix
➀U = Unified
20
43 to 49
2.0M
M = Metric
Tapered Threads
Introduction
Identification
Tables
The following characteristics and information should
be considered when using tapered threads:
■ The seal is designed to take place between the
tapered threads.
■ Tapered pipe threads always need a sealant to
seal system fluids and reduce the potential for
galling of the threads.
■ Products such as Swagelok PTFE tape, SWAK®,
anaerobic pipe thread sealant with PTFE, and
PTFE Free pipe thread sealant perform both
the lubricating and sealing functions. If the two
pieces of metal are forced against each other
without lubrication, galling is possible.
■ After following the sealant and lubricant application
instructions, the amount of tightening is
discretionary. There is no standard for torque or
number of turns.
Tapered
Straight
Appendix
21
Tapered Threads
Introduction
CAJON THREAD ID
NPT
60°
(also known as
ASME B1.20.1)
Characteristics
■ Tapered thread (1° 47')
Identification
■ Truncation of roots
and crests are flat
■ 60° thread angle
■ Pitch is measured in
threads per inch
1° 47'
55°
Tables
ISO 7/1
(also known as
EN 10226‑1 and
JIS B0203)
Characteristics
Tapered
■ Tapered thread (1° 47')
■ Truncation of roots and
crests are rounded
■ 55° thread angle
■ Pitch is measured in
Appendix
Straight
threads per inch
22
1° 47'
End Connections That Use
Introduction
Tapered Threads
■ NPT
■ NPT with O-Seal
■ BSPT
Nominal
Size
in.
NPT
NPT with O-Seal
ISO 7/1
1/16
1/16-27
1/16-27
1/16-28
1/8
1/8-27
1/8-27
1/8-28
1/4
1/4-18
1/4-18
1/4-19
3/8
3/8-18
3/8-18
3/8-19
1/2
1/2-14
1/2-14
1/2-14
3/4
3/4-14
3/4-14
3/4-14
1
1-11.5
1-11.5
1-11
1 1/4
1 1/4-11.5
1 1/4-11.5
1 1/4-11
1 1/2
1 1/2-11.5
1 1/2-11.5
1 1/2-11
2
2-11.5
2-11.5
2-11
Identification
Thread Size-Pitch
Tables
Tapered
Note:1/2 and 3/4 in. BSPT and NPT threads can be difficult to
identify because they are very close in design. Positive
identification may not be possible without the use of an
optical comparator. Contact your authorized Swagelok
sales and service center for additional information.
Straight
Appendix
23
End Connections That Use
Introduction
Tapered Threads
Identification
NPT
Tables
Applicable Standards
Seal Location
Fittings
Thread
On threads
(sealant required)
NPT
ASME B1.20.1
Male: The male end has a 1° 47' tapered thread
with a 60° thread angle.
Tapered
Female:The female end has a 1° 47' tapered
thread with a 60° thread angle.
Appendix
Straight
Seal:The seal is designed to take place on the
tapered thread.
24
End Connections That Use
Introduction
Tapered Threads
NPT with O-Seal
Identification
Tables
O-ring
Tapered
Applicable Standards
Seal Location
Fittings
Thread
O-ring compression
None
ASME B1.20.1
Straight
Male:The male end has an undersized NPT
thread and an O-ring groove on the
shoulder of the hex.
Female:The female end has an NPT thread and a
smooth, flat surface.
Seal:The seal takes place by compressing the
O-ring against the face of the female
component.
Appendix
25
End Connections That Use
Introduction
Tapered Threads
BSPT
JIS R and JIS Rc
Tables
Identification
DIN 3852 Part 2, Type C
Tapered
Applicable Standards
Seal Location
Fittings
Thread
On threads
(sealant required)
JIS B8363
BS 5200
DIN 3852 Part 2
ISO 7/1
Male: The male end has a 1° 47' tapered thread
with a 55° thread angle.
Female:The female end has a 1° 47' tapered
thread with a 55° thread angle.
Appendix
Straight
Seal:The seal is designed to take place on the
tapered thread.
26
Straight Threads
Introduction
Identification
Worldwide, there are many end connections available
with straight threads. Each end connection,
however, will generally have threads that are one of
the three most common: ASME B1.1 (unified screw
thread), ISO 228/1, or ISO 261 straight threads.
Because the threads of the mating fittings are parallel
to each other, there is no interference between the
flanks, crests, and roots. Consequently, the seal must
be made with a gasket, O-ring, or some metal to metal
contact. A sealant is not required or recommended
on straight threads. Depending on the application
and materials, thread lubricant may be used.
Unified Screw Thread
(also known as ASME B1.1)
■ Straight thread
Tables
Characteristics
60°
■ Truncation of roots
and crests are flat
■ 60° flank angle
■ Diameter and pitch
Tapered
measured in inches
Thread Series
■ UN: Male and female screw thread
■ UNR: Male screw thread only (more rounded crest)
■ UNC/UNRC: Coarse thread series
■ UNF/UNRF: Fine thread series
Straight
■ UNEF/UNREF: Extra-fine thread series
■ UNS/UNRS: Selected special combinations of
diameters, pitches, and lengths of engagement.
Appendix
27
Introduction
Straight Threads
ISO 228/1
(also known as BSPP, JIS
B0202)
Characteristics
55°
■ Straight thread
Identification
■ Truncation of roots and
crests are rounded
■ 55° flank angle
■ Threads are measured
in inches
Metric
Tables
(also known as ISO
261, JIS B0205, ASME
B1.13M)
60°
Characteristics
■ Straight thread
■ Truncation of roots
and crests are flat
Tapered
■ 60° flank angle
■ Threads are measured
in millimeters
NPSM
Straight
(also known as ASME
B1.20.1)
Characteristics
■ Straight thread
■ Truncation of roots
and crests are flat
■ 60° flank angle
Appendix
■ Threads are measured
in inches
28
60°
End Connections That Use
Introduction
Unified Screw Threads
■ SAE 37° (JIC)
■ SAE Straight Thread O-Ring Boss
■ Straight Thread O-Seal
■ SAE 45°
Identification
■ SAE J1453 O-Ring Face Seal
■ ISO 8434-3
■ SAE 42° Inverted Flare
SAE (Society of Automotive Engineers)
Fitting Types
37°
O-Ring
Boss
O-Seal
45°
J1453
Inverted
42°
Flare
5/16-28
1/8
5/16-24
5/16-24
5/16-24
5/16-24
—
3/16
3/8-24
3/8-24
3/8-24
3/8-24
—
3/8-24
1/4
7/16-20
7/16-20
7/16-20
7/16-20
9/16-18
7/16-24
1/2-20
1/2-20
1/2-20
1/2-20
—
9/16-18
9/16-18
9/16-18
5/8-18
11/16-16
5/8-18
7/16
—
—
—
11/16-16
—
11/16-16
1/2
3/4-16
3/4-16
3/4-16
3/4-16
13/16-16
3/4-16
5/8
7/8-14
7/8-14
7/8-14
7/8-14
1-14
7/8-14
3/4
1 1/16-12 1 1/16-12 1 1/16-12 1 1/16-14 1 3/16-12 1 1/16-1
7/8
1 3/16-12 1 3/16-12 1 3/16-12 1 1/4-12
—
1 1/4-12
1
1 5/16-12 1 5/16-12 1 5/16-12
—
1 7/16-12
—
1 1/4
1 5/8-12 1 5/8-12 1 5/8-12
—
1 11/16-12
—
1 1/2
1 7/8-12 1 7/8-12 1 7/8-12
—
2-12
—
2
2 1/2-12 2 1/2-12 2 1/2-12
—
—
—
Straight
1/2-20
3/8
Tapered
5/16
Tables
Thread Size-Pitch
Nominal
Size
in.
Appendix
29
End Connections That Use
Introduction
Unified Screw Threads
Identification
SAE 37° (JIC)
Tables
Gland
Sleeve
Tapered
Tubing
Straight
Applicable Standards
Seal Location
Fittings
Thread
Mating 37°
flared surfaces
SAE J514
ASME B1.1
Male:The male end has a straight thread and a
37° cone taper.
Appendix
Female:The female end has a straight thread and
a nut captured on tubing with a mating 37°
flare or a 37° tapered gland.
Seal: The seal takes place between the male
taper and the inside diameter of the
tapered gland or flared tubing.
30
End Connections That Use
Introduction
Unified Screw Threads
SAE Straight Thread O-Ring Boss
Identification
Tables
O-ring
Fittings
Thread
O-ring compression
SAE J1926, ISO 11926
ASME B1.1
Tapered
Applicable Standards
Seal Location
Male:The male end has a straight thread and
an O-ring.
Seal:The seal takes place by compressing the
O-ring into the taper.
Straight
Female: The female end has a straight thread and a
taper to accept the O-ring.
Appendix
31
Unified Screw Threads
Straight Thread O-Seal
Tables
Identification
Introduction
End Connections That Use
O-ring
Tapered
Applicable Standards
Seal Location
Fittings
Thread
O-ring compression
None
ASME B1.1
Female:The female end has a straight thread and a
smooth, flat surface.
Seal:The seal takes place by compressing
the O-ring against the face of the female
component.
Appendix
Straight
Male:The male end has a straight thread and an
O-ring groove on the shoulder of the hex.
32
End Connections That Use
Introduction
Unified Screw Threads
SAE 45°
Identification
Gland
Tables
Tubing
Sleeve
Tapered
Applicable Standards
Fittings
Thread
Mating 45°
flared surface
SAE J512
SAE J513
ASME B1.1
Male:
Straight
Seal Location
The male end has a straight thread and
a 45° cone taper.
Female: The female end has a straight thread
and a nut captured on tubing with a
mating 45° flare or a 45° tapered gland.
Appendix
Seal:
The seal takes place between the male
taper and the inside diameter of the
tapered gland or flared tubing.
33
Unified Screw Threads
SAE J1453 O-Ring Face Seal
ISO 8434-3
Tables
Identification
Introduction
End Connections That Use
O-ring
Fittings
Thread
O-ring compression
face of fitting
SAE J1453
ISO 8434-3
ASME B1.1
Male:The male end has a straight thread and
an O-ring in a groove on the face of the
fitting.
Female: The female end has a straight thread. A
gland with a flat face is held against the
body by a female nut that threads onto
the body.
Seal:The seal takes place by compressing the
O-ring between the faces of the fitting.
Appendix
Straight
Tapered
Applicable Standards
Seal Location
34
End Connections That Use
Introduction
Unified Screw Threads
SAE 42° Inverted Flare
Identification
Without Flared Tubing
Tables
Tapered
With Flared Tubing
Applicable Standards
Fittings
Thread
Mating angled
and flared surfaces
SAE J512
ASME B1.1
Straight
Seal Location
Male:The male end has a straight thread and
can have either a 42° or 45° taper.
Seal:The seal takes place between the taper
in the male fitting and flared tubing or
directly on the inverted flare seat.
35
Appendix
Female:The female end has a straight thread and a
42° inverted flare seat or gland.
End Connections That Use
Introduction
ISO 228/1 Threads
■ BSPP (British Standard Pipe Parallel)
JIS Parallel Pipe
■ JIS 30° Flare
■ DIN EN 837-1 and DIN EN 837-3, Type B
Identification
■ DIN 3852 Part 2, Type A
■ DIN 3852 Part 2, Type B
■ BS 5380 (British Standard)
Thread Size-Pitch, in.
Tapered
Tables
Nominal
Size
in.
Appendix
DIN
3852
Part 2,
Type B
1/16
—
—
—
—
1/16-28
—
1/8
1/8-28
—
1/8-28
1/8-28
1/8-28
1/8-28
1/4
1/4-19
1/4-19
1/4-19
1/4-19
1/4-19
1/4-19
3/8
3/8-19
3/8-19
—
3/8-19
3/8-19
3/8-19
1/2
1/2-14
1/2-14
1/2-14
1/2-14
1/2-14
1/2-14
5/8
5/8-14
—
—
5/8-14
5/8-14
5/8-14
3/4
3/4-14
3/4-14
—
3/4-14
3/4-14
3/4-14
7/8
—
—
—
7/8-14
7/8-14
—
1
1-11
1-11
—
1-11
1-11
1-11
BS
5380
—
—
—
1 1/8-11 1 1/8-11
1 1/4
1 1/4-11 1 1/4-11
—
1 1/4-11 1 1/4-11 1 1/4-11
1 1/2
—
1 1/2-11 1 1/2-11
—
1 1/2-11 1 1/2-11 1 1/2-11
1 3/4
—
—
—
1 3/4-11 1 3/4-11
2
2-11
2-11
—
➀ Also known as JIS parallel pipe.
36
DIN
3852
Part 2,
Type A
BSPP➀
1 1/8
Straight
DIN EN
837-1,
DIN EN
837-3
JIS 30°
Flare
2-11
2-11
—
2-11
End Connections That Use
Introduction
ISO 228/1 Threads
BSPP
(British Standard Pipe Parallel)
JIS Parallel Pipe
Identification
Tables
Applicable Standards
Fittings
Thread
Mating 30° angled
Surfaces or O-ring
Compression
BS 5200
JIS B8363
ISO 228/1
Tapered
Seal Location
BSPP and JIS parallel pipe fittings are identical in design,
appearance, and dimensions.
Male: The male end has a straight thread and a
30° taper.
Straight
Female:The female end is a nut with a straight
thread captured on a 30° cone tapered
gland.
Seal:The seal takes place between the taper
in the male fitting and the 30° cone
tapered gland.
Appendix
37
ISO 228/1 Threads
JIS 30° Flare
Identification
Introduction
End Connections That Use
Tables
Gland
Sleeve
Tapered
Tubing
Straight
Applicable Standards
Seal Location
Fittings
Thread
Mating 30° angled
or flared surfaces
JIS B8363
ISO 228/1
Male:The male end has a straight thread and a
30° cone taper.
Appendix
Female:The female end has a straight thread and
a nut captured on tubing with a mating 30°
flare or a 30° tapered gland.
Seal:The seal takes place between the male
taper and the ID of the tapered gland or
flared tubing.
38
End Connections That Use
Introduction
ISO 228/1 Threads
DIN EN 837-1 and DIN EN 837-3, Type B
JIS B0202
Female ➀
Identification
Gasket
Tables
Female ➁
Counterbore
Gasket
Tapered
Applicable Standards
Seal Location
Fittings
Thread
Gasket compression
DIN EN 837-1, 837-3
ISO 228/1, JIS B0202
Appendix
39
Straight
Male:The male fitting has a straight thread
and a spigot which fits through the inside
diameter of the gasket.
➀ Female:
The female has a straight thread and a
counterbore in the inside diameter of the
fitting to accept a gasket.
➁ Female:The female has a straight thread and
a counterbore in the inside diameter
of the fitting to accept a gasket. The
counterbore is larger to help ensure the
male end compresses the gasket into a
sealing position.
Seal:The seal takes place by compressing a
gasket between the male and female fittings.
ISO 228/1 Threads
DIN 3852 Part 2, Type A
Identification
Introduction
End Connections That Use
Bonded gasket
Tapered
Tables
Shoulder
Applicable Standards
Seal Location
Fittings
Thread
Gasket compression
DIN 3852 Part 2
ISO 228/1
Male:The male end has a straight thread and
a straight shoulder.
Female:The female end has a straight thread and a
flat, smooth surface.
Gasket:This gasket could be either all metal or
metal with a bonded elastomer on the
inside diameter.
Appendix
Straight
Seal:The seal takes place by compressing a
gasket between the straight shoulder and
the flat, smooth surface.
40
End Connections That Use
Introduction
ISO 228/1 Threads
DIN 3852 Part 2, Type B
Identification
All-metal gasket
Shoulder
Tables
Tapered
Applicable Standards
Fittings
Thread
Gasket metal-to-metal
DIN 3852 Part 2
ISO 228/1
Straight
Seal Location
Male:The male end has a straight thread and an
angled shoulder.
Female:The female end has a straight thread and a
flat, smooth surface.
Appendix
Seal:The seal takes place by compressing a
gasket between the angled shoulder and
the flat, smooth surface.
Gasket:Use of a metal gasket is suggested.
41
End Connections That Use
Introduction
ISO 228/1 Threads
Tables
Identification
BS 5380 (British Standard)
O-ring
Tapered
Applicable Standards
Seal Location
Fittings
Thread
O-ring compression
BS 5380
ISO 228/1
Male:The male end has a straight thread and
an O-ring.
Straight
Female:The female end has a straight thread and a
taper to accept the O-ring.
Appendix
Seal:The seal takes place by compressing the
O-ring into the taper.
42
End Connections That Use
Introduction
Metric (ISO 261) Threads
■ DIN 7631
■ JIS Parallel Pipe Metric
■ DIN EN 837-1 and DIN EN 837-3, Type B
■ DIN 3852 Part 1, Type A
■ DIN 3852 Part 1, Type B
Identification
■ ISO 6149-1, ISO 6149-2, and ISO 6149-3
Thread Size-Pitch
Nominal
Size
mm
DIN
7631
JIS
Parallel
Pipe
Metric
DIN EN
837-1,
DIN EN
837-3
DIN
3852
Part 1
Type A
DIN
3852
Part 1
Type B
ISO
6149-1,
6149-2,
6149-3
—
—
—
M8 × 1
M8 × 1
M8 × 1
M10 × 1
—
M10 × 1
M10 × 1
M10 × 1
M10 × 1
M12
M12 × 1.5
—
M12 × 1.5 M12 × 1.5 M12 × 1.5 M12 × 1.5
M14
M14 × 1.5 M14 × 1.5
M16
M16 × 1.5
M18
M18 × 1.5 M18 × 1.5
M20
M22
—
—
—
—
M14 × 1.5 M14 × 1.5 M14× 1.5
—
M16 × 1.5 M16 × 1.5 M16 × 1.5
—
M18 × 1.5 M18 × 1.5 M18 × 1.5
M20 × 1.5 M20 × 1.5 M20 × 1.5 M20 × 1.5
—
M22 × 1.5 M22 × 1.5 M22 × 1.5
M24
—
—
—
M24 × 1.5 M24 × 1.5
M26
M26 × 1.5
—
—
M26 × 1.5 M26 × 1.5 M26 × 1.5
—
M27 × 2.0
—
M27 × 2.0 M27 × 2.0 M27 × 2.0
—
—
M30 × 1.5 M30 × 1.5
—
—
—
—
M30 × 2.0 M30 × 2.0
—
—
M33 × 2.0
—
M30 × 2.0 M30 × 2.0 M30 × 2.0
—
—
—
M36 × 1.5 M36 × 1.5
—
—
—
—
M36 × 2.0 M36 × 2.0
—
M38
M38 × 1.5
—
—
M38 × 1.5 M38 × 1.5
—
M39
—
—
—
M39 × 1.5 M39 × 1.5
—
—
M42 × 1.5
—
M42 × 2.0 M42 × 2.0 M42 × 2.0
M30
M33
M36
M42
—
—
—
M42 × 2.0 M42 × 2.0
—
M45 × 2.0
—
—
M45 × 1.5 M45 × 1.5
—
—
—
—
M45 × 2.0 M45 × 2.0
—
—
—
—
M48 × 1.5 M48 × 1.5 M48 × 2.0
—
—
—
M48 × 2.0 M48 × 2.0
—
M50 × 2.0
—
M52 × 1.5
—
—
M52 × 1.5 M52 × 1.5
—
—
—
—
M52 × 2.0 M52 × 2.0
—
M56
—
—
—
M56 × 2.0 M56 × 2.0
—
M60
—
M60 × 2.0
—
M60 × 2.0 M60 × 2.0 M60 × 2.0
M45
M48
M50
—
—
M50 × 2.0
Appendix
M52
—
Straight
—
M30 × 1.5
Tapered
M27
M22 × 1.5 M22 × 1.5
Tables
M8
M10
43
Introduction
End Connections That Use
Metric (ISO 261) Threads
DIN 7631
Tapered
Tables
Identification
O-ring
O-ring
Appendix
Straight
Applicable Standards
Seal Location
Fittings
Thread
Globe seal nose
tapered angle
DIN 7631
Metric (ISO 261)
Male:The male end has a straight thread and a
30° taper.
Female:The female end is a nut with a straight
thread captured on a globe seal nose
gland. The globe seal nose may contain
an O-ring.
Seal:The seal takes place between the taper in
the male fitting and the globe seal nose.
44
End Connections That Use
Introduction
Metric (ISO 261) Threads
JIS Parallel Pipe Metric
Identification
Tables
Applicable Standards
Seal Location
Fittings
Thread
Mating 30°
angled surfaces
JIS B8363
Metric (ISO 261)
Male:The male end has a straight thread and a
30° taper.
Tapered
Female:
The female end is a nut with a straight
thread captured on a 30° cone tapered
gland.
Seal: The seal takes place between the taper
in the male fitting and the 30° cone
tapered gland.
Straight
Appendix
45
Introduction
End Connections That Use
Metric (ISO 261) Threads
DIN EN 837-1 and DIN EN 837-3, Type B
Identification
Female ➀
Gasket
Female ➁
Tables
Counterbore
Appendix
Straight
Tapered
Gasket
Applicable Standards
Seal Location
Fittings
Thread
Gasket compression
DIN EN 837-1
and DIN EN 837-3
Metric (ISO 261)
Male:The male fitting has a straight thread
and a spigot which fits through the inside
diameter of the gasket.
➀ Female:
The female has a straight thread and a
counterbore in the inside diameter of the
fitting to accept a gasket.
➁ Female:The female has a straight thread and
a counterbore in the inside diameter
of the fitting to accept a gasket. The
counterbore is larger to help ensure the
male end compresses the gasket into a
sealing position.
Seal:The seal takes place by compressing a
gasket between the male and female fittings.
46
End Connections That Use
Introduction
Metric (ISO 261) Threads
DIN 3852 Part 1, Type A
Identification
Bonded gasket
Shoulder
Tables
Applicable Standards
Seal Location
Fittings
Thread
Gasket compression
DIN 3852 Part 1
Metric (ISO 261)
Male:The male end has a straight thread and
a straight shoulder.
Tapered
Female:The female end has a straight thread and a
flat, smooth surface.
Seal:The seal takes place by compressing a
gasket between the straight shoulder and
the flat, smooth surface.
Straight
Gasket:This gasket could be either all metal or
metal with a bonded elastomer on the
inside diameter.
Appendix
47
Metric (ISO 261) Threads
DIN 3852 Part 1, Type B
Identification
Introduction
End Connections That Use
All-metal gasket
Tapered
Tables
Shoulder
Straight
Applicable Standards
Seal Location
Fittings
Thread
Gasket metal-to-metal
DIN 3852 Part 1
Metric (ISO 261)
Male:The male end has a straight thread and an
angled shoulder.
Appendix
Female:The female end has a straight thread and a
flat, smooth surface.
Seal:The seal takes place by compressing a
gasket between the angled shoulder and
the flat, smooth surface.
Gasket:Use of a metal gasket is suggested.
48
End Connections That Use
Introduction
Metric (ISO 261) Threads
ISO 6149-1, ISO 6149-2, AND ISO 6149-3
Identification
Tables
O-ring
Applicable Standards
Fittings
Thread
O-ring compression
ISO 6149-1,
ISO 6149-2,
ISO 6149-3
Metric (ISO 261)
Tapered
Seal Location
Male:The male end has a straight thread and
an O-ring.
Seal:The seal takes place by compressing the
O-ring into the taper.
Straight
Female: The female end has a straight thread and a
taper to accept the O-ring.
Appendix
49
NPSM Threads
NPSM
Identification
Introduction
End Connections That Use
Straight
Tapered
Tables
Applicable Standards
Fittings
Thread
NPSM
ASME B1.20.1
Nominal
Size, in.
NPSM
Thread SIze-Pitch
1/8
1/8-27
1/4
1/4-18
3/8
3/8-18
1/2
1/2-14
3/4
3/4-14
1
1-11.5
1 1/4
1 1/4-11.5
1 1/2
1 1/2-11.5
2
2-11.5
Male:The male end has a straight thread and
a 30° taper.
Appendix
Female:The female end is a nut with a straight
thread captured on a 30° cone tapered
gland.
Seal:The seal takes place between the taper in
the male fitting and the 30° cone tapered
gland.
50
End Connection to Thread Matrix
Page
Thread Standard
Page
BSP (British Pipe Standard)
BSPP (5200)
37
ISO 228/1
28
BS 5380
42
ISO 228/1
28
Introduction
End Connection
DIN (Deutsches Institut für Normung e.V.)
39
ISO 228/1
28
DIN EN 837-1 and
DIN EN 837-3, Type B
46
Metric (ISO 261)
28
DIN 3852 Part 1, Type A
47
Metric (ISO 261)
DIN 3852 Part 1, Type B
48
Metric (ISO 261)
DIN 3852 Part 2, Type A
40
ISO 228/1
41
ISO 228/1
26
ISO 7/1
ISO 6149-1, ISO 6149-2,
and ISO 6149-3
49
Metric (ISO 261)
DIN 7631
44
Metric (ISO 261)
28
22
Tables
DIN 3852 Part 2, Type B
DIN 3852 Part 2, Type C
Identification
DIN EN 837-1 and
DIN EN 837-3, Type B
28
JIS (Japanese Industrial Standard)
38
JIS (B8363)
37
ISO 228/1
ISO 228/1
JIS (B8363)
45
Metric (ISO 261)
JIS (B8363)
26
ISO 7/1
28
Tapered
JIS 30° Flare (B8363)
NPSM (National Pipe Straight Mechanical)
NPSM
50
ASME B1.20.1
28
NPT (National Pipe Taper)
NPT
24
ASME B1.20.1
22
SAE (Society of Automotive Engineers)
34
SAE 37° (JIC) (J514)
30
SAE 42° Inverted Flare (J512)
35
SAE 45° (J512, J513)
33
SAE Straight Thread
O-Ring Boss (J1926)
31
ASME B1.1
Straight
SAE J1453 O-Ring Face Seal
27
Appendix
51
Introduction
Thread to End Connection Matrix
Thread Standard
Page
End Connection
Page
ISO 7/1
EN 10226-1
JIS B0203
22
DIN 3852 Part 2, Type C
JIS (B8363)
26
Identification
ISO 228/1
ISO 228/1
28
JIS B0202
BSPP (5200)
37
DIN EN 837-1 and
DIN EN 837-3, Type B
39
DIN 3852 Part 2, Type A
40
DIN 3852 Part 2, Type B
41
JIS 30° Flare (B8363)
38
JIS (B8363)
37
DIN EN 837-1 and
DIN EN 837-3, Type B
46
Tables
Metric
ISO 261
DIN 3852 Part 1, Type A
47
DIN 3852 Part 1, Type B
48
DIN 3852 Part 1
49
DIN 7631
44
JIS (B8363)
45
28
NPSM
50
22
NPT
24
28
ASME B1.13M
JIS B0205
Tapered
ASME B1.20.1
ASME B1.20.1
Unified Screw Thread ASME B1.1
Appendix
Straight
ASME B1.1
52
27
SAE J1453 O-Ring
Face Seal
34
SAE 37° (JIC) (J514)
30
SAE 42° Inverted
Flare (J512)
35
SAE 45° (J512, J513)
33
SAE Straight Thread
O-Ring Boss (J1926)
31
Thread Identification Tools
Introduction
Caliper
A caliper is used to determine the thread diameter.
(Calibration of calipers is the responsibility of the
end user.)
Identification
Tapered
Seat and pitch gauges are conveniently combined
into one tool.
The seat gauge is used to determine end connection
seat angles of 45°, 37°, and 30°.
The pitch gauge is used to identify the thread pitch.
Note that a pitch gauge may be Unified (threads
per inch), Whitworth (threads per inch), or metric
(millimeters per thread) as marked on the back of
each gauge form.
Tables
Combination Seat and Pitch Gauge
Thread pitch gauges
Straight
Seat angle gauges
Appendix
53
Glossary
Introduction
ASMEB1.1. See Unified Screw Threads.
B1.20.1. See NPT.
B1.13M. See ISO 261.
BSPP
British Standard Pipe Parallel per
ISO 228/1.
Identification
BSPTBritish Standard Pipe Tapered per
EN 10226-1. See ISO 7/1.
DINDeutsche Institut für Normung e.V.
ISO 228/1International Standards Organization
Specification 228/1, straight threads,
reference specification: BSPP,
DIN 259, JIS B0202.
Tables
ISO 261International Standards Organization
Specification 261, straight threads,
metric measurements, often referred
to as the “pure metric straight”
fitting, JIS B0205.
Tapered
ISO 7/1International Standards Organization
Specification 7/1, tapered threads,
imperial measurements, reference
specifications: EN 10226-1 (male
thread only), JIS B0203.
JISJapanese Industrial Standard.
JIS B0202Japanese Industrial Standard B0202.
See ISO 228/1.
Straight
JIS B0203Japanese Industrial Standard
B0203. See ISO 7/1.
Appendix
JIS B0205Japanese Industrial Standard
B0205. See ISO 261.
54
Metric
See ISO 261.
Metric
Straight
See ISO 261.
Glossary
National Pipe Tapered.
Introduction
NPT
SAE
Society of Automotive Engineers.
UN
Unified Constant-Pitch Thread Series.
UNC/UNRC
Unified Coarse Thread Series.
Identification
PitchFor the purposes of this guide, pitch
refers to threads per inch, instead of
the distance between the threads,
for fractional screw threads and
pipe threads. For all metric screw
threads, pitch refers to the distance
between adjacent threads.
UNEF/UNREF Unified Extra-Fine Thread Series.
Unified Fine Thread Series.
UNR
Male Screw Thread only.
Tables
UNF/UNRF
UNS/UNRSSelected special combinations
of diameter, pitch, and length of
engagement.
See ASME B1.1 and ASME B1.20.1.
Whitworth
See ISO 228/1 and ISO 7/1.
Tapered
Unified
Straight
Appendix
55
Identification
Introduction
Safe Product Selection
When selecting a product, the total system
design must be considered to ensure safe,
trouble-free performance. Function, material
compatibility, adequate ratings, proper
installation, operation, and maintenance are
the responsibilities of the system designer
and user. The complete catalog contents
must be reviewed to ensure that the system
designer and user make a safe product
selection.
• WARNING
Tables
Do not mix/interchange Swagelok products
or components not governed by industrial
design standards, including Swagelok tube
fitting end connections, with those of other
manufacturers.
Warranty Information
Appendix
Straight
Tapered
Swagelok products are backed by The Swagelok
Limited Lifetime Warranty. For a copy, visit
swagelok.com or contact your authorized
Swagelok representative.
56
57
Swagelok, SWAK­—TM Swagelok Company
© 2015–2021 Swagelok Company
Printed in U.S.A., AGS
August 2021, RevG
MS-13-77